Cell stacking method

Abstract

The present invention relates to a cell stacking method including the steps of setting a virtual reference line at the center of a cell and stacking a plurality of cells with the reference line set thereon, wherein the stacked cells are stacked in a state where the reference lines are aligned.

Description

[Technical Field]

[0001] The present invention relates to a cell stacking method, characterized in that a virtual reference line is set on each cell, and the cells are aligned so that the reference lines coincide with each other.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0005584, filed on January 13, 2023, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Secondary batteries, which are easily applicable to various products and have electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles or hybrid vehicles powered by electrical sources, power storage devices, etc. These secondary batteries are attracting attention as a new energy source for improving energy efficiency, as they are environmentally friendly in that they do not produce any by-products from energy use, in addition to their primary advantage of dramatically reducing the use of fossil fuels.

[0004] Small mobile devices use one or two to four battery cells per device, while medium to large devices such as automobiles require high output and large capacity. Therefore, medium to large battery modules, which electrically connect multiple battery cells, are used.

[0005] Since it is preferable that medium- to large-sized battery modules be manufactured with the smallest possible size and weight, prismatic batteries, pouch-shaped batteries, etc., which can be stacked with a high degree of integration and have a small weight relative to their capacity, are mainly used as battery cells for medium- to large-sized battery modules.

[0006] Generally, a battery module may include a frame member having an open front and rear surface and housing a cell stack in an internal space to protect the cell stack from external impact, heat, or vibration.

[0007] Meanwhile, in a cell stack in which a plurality of battery cells are stacked, the alignment of the battery cells is one of the important issues that affect the performance of the secondary battery.

[0008] Before stacking the battery cells C, the position of each battery cell C is corrected as shown in Figure 1, and then the battery cells C are stacked. However, at this time, slight imbalances in position may occur due to structural limitations of the battery cells C, etc.

[0009] FIG. 2 shows a cell stack Cs included in a battery module, and it can be seen that the battery cells C, in which the positive electrode lead L1 and the negative electrode lead L2 are positioned opposite each other, are misaligned in the vertical direction on the drawing.

[0010] When the positions of the battery cells C included in the cell stack Cs are slightly shifted in this manner, a contact error may occur between the electrode leads Le and the bus bars B electrically connected to the electrode leads Le. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Korean Patent Publication No. 10-2021-0049471 Summary of the Invention [Problem to be solved by the invention]

[0012] SUMMARY OF THE INVENTION Accordingly, the present invention has been devised to solve the above problems, and an object of the present invention is to provide a cell stacking method that can improve the alignment of each cell during cell stacking.

[0013] Other objects and advantages of the present invention will become apparent from the following description and become more clearly apparent from the embodiments of the present invention. Also, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed. [Means for solving the problem]

[0014] According to the present invention, there is provided a cell stacking method including the steps of setting a virtual reference line at the center of a cell and stacking a plurality of cells having the reference line set thereon, wherein the stacked cells are aligned and stacked so that the reference lines coincide with each other.

[0015] The cell accommodates an electrode assembly in which a plurality of electrodes are stacked, and electrode leads electrically connected to the electrode assembly may be led out from both sides of the cell.

[0016] A reference line may be set at a position corresponding to the center of the uppermost electrode of the electrode assembly.

[0017] The cell may be composed of a receiving portion in which the electrode assembly is located and a lead-out portion in which an electrode lead is located.

[0018] A step may be formed between the receiving portion and the outlet portion, and the central portion may correspond to a center position with respect to a position where the step begins on both sides of the receiving portion.

[0019] The center of the cell may correspond to a center position when the edges of both ends of the storage section are taken as starting points.

[0020] The center of the cell may correspond to a position that is halfway between the edge positions of both ends of the receiving portion.

[0021] The reference line may be formed across the center of the cell with electrode leads located on either side.

[0022] The reference line may correspond to a center position with respect to both ends of the uppermost electrode of the electrode assembly as origins.

[0023] The electrode assembly includes a positive electrode, a separator, and a negative electrode, and the electrode lead includes a positive electrode lead electrically connected to the positive electrode of the electrode assembly and a negative electrode lead electrically connected to the negative electrode of the electrode assembly, and the adjacent pair of cells may be stacked alternately such that the positions of the positive electrode lead and the negative electrode lead are reversed.

[0024] The positions of the cells can be adjusted by moving them horizontally so that the reference lines coincide with each other. [Effects of the Invention]

[0025] According to the present invention, the alignment of each cell can be improved during stacking of cells, thereby improving the stability of the secondary battery. [Brief explanation of the drawings]

[0026] [Figure 1] 1 shows a conventional process for forming a cell stack. [Figure 2] 1 shows a cell stack included in a conventional battery module. [Figure 3] 1 shows a flowchart of a cell stacking method of the present invention. [Figure 4] 1 shows a cell and a visual sensor used in a cell stacking method according to a first embodiment of the present invention. [Figure 5] This is a side view of the cell and visual sensor shown in Figure 4 above. [Figure 6] The boundary between the storage section and the outlet section of the cell is shown. [Figure 7] This shows the process of stacking multiple cells. [Figure 8] 10 shows a cell and a visual sensor used in a cell stacking method according to a second embodiment of the present invention. [Figure 9] 9 shows the cell and visual sensor of FIG. 8 from the side. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concepts of the terms to best describe his own invention.

[0028] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0029] Furthermore, in the description of the present invention, if it is determined that a detailed description of related publicly known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0030] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown in a schematic manner for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0031] The present invention relates to a cell stacking method, characterized in that a virtual reference line is set on each cell, and the cells are aligned and stacked so that the reference lines coincide with each other.

[0032] A certain number of cells are stacked to form a cell stack, and the cell stack thus formed is combined with bus bars electrically connecting each cell and a frame surrounding the outer surface to protect the cell stack, thereby forming a battery module.

[0033] 3 shows a flowchart of the cell stacking method of the present invention. Hereinafter, the cell stacking method of the present invention will be described step by step with reference to the flowchart.

[0034] (First embodiment) Reference line BL setting step (S1)

[0035] This is the step of setting a virtual reference line BL at the center of the cell C.

[0036] The center of the cell C can be found by identifying the edges Co on both sides of the cell C with the visual sensor S.

[0037] FIG. 4 shows a cell C used in the cell C stacking method according to the first embodiment of the present invention and a visual sensor S used to locate the center of the cell C, and FIG. 5 shows the cell C and visual sensor S of FIG. 4 from a side view.

[0038] The cell C houses an electrode assembly (not shown) in which multiple electrodes are stacked, and as shown in Figures 4 and 5, electrode leads Le are led out from both sides of the cell C, electrically connected to the electrode assembly.

[0039] The electrode assembly includes a positive electrode, a separator, and a negative electrode, and the positive electrode, the separator, and the negative electrode are alternately stacked.

[0040] The electrode lead Le includes a positive electrode lead L1 electrically connected to the positive electrode of the electrode assembly, and a negative electrode lead L2 electrically connected to the negative electrode of the electrode assembly.

[0041] Adjacent pairs of cells C can be stacked alternately so that the positions of the positive electrode lead L1 and the negative electrode lead L2 are opposite, or several cells can be stacked in pairs so that the positive electrode lead L1 and the negative electrode lead L2 are in the same positions.

[0042] As shown in FIG. 5, the cell C is composed of a receiving portion Pr and a leading portion Pe.

[0043] An electrode assembly may be positioned in the receiving portion Pr, and an electrode lead Le may be positioned in the leading portion Pe.

[0044] A step is formed between the receiving portion Pr and the lead-out portion Pe, and the height of the step may vary depending on the thickness of the electrode assembly included in the receiving portion Pr.

[0045] The cell C stacking method of the present invention is characterized in that a virtual reference line BL is set for each cell C to be stacked, and when stacking each cell C, the reference lines BL are aligned so that they coincide with each other.

[0046] The reference line BL corresponds to the center of the cell C, and the center of each cell C is found using the positions of both ends of the receiving portion Pr of the cell C as references.

[0047] That is, the center is the position that is halfway between the positions of both ends of the housing portion Pr.

[0048] The center of the cell C corresponds to the center of the electrode assembly, and the reference line BL is formed to pass through the center of the cell C. More specifically, the reference line BL is formed to cross the center of the cell C so that the electrode leads Le of the cell C are located on both sides of the reference line BL.

[0049] The reference line BL is set at a position corresponding to the center of the uppermost electrode of the electrode assembly contained in the housing portion Pr, i.e., the reference line BL is formed at a center position with both ends of the uppermost electrode of the electrode assembly as origins.

[0050] Both ends of the electrode included in the uppermost part of the electrode assembly correspond to the boundary between the receiving portion Pr and the lead-out portion Pe, or correspond to the positions where the steps start on both sides of the receiving portion Pr.

[0051] FIG. 6 shows the boundary between the receiving portion Pr and the outlet portion Pe of the cell C.

[0052] The positions where the steps start at both ends of the electrode included in the uppermost part of the electrode assembly or at the boundary between the receiving part Pr and the leading part Pe correspond to the ends of the uppermost electrode as shown in FIG.

[0053] The positions of the edges of the stacked electrodes may vary slightly, as shown in Fig. 6. In the present invention, in order to quickly locate the center of the cell C and set the reference line BL, both edges of the electrode located at the top of the electrode assembly are identified, and the center of the electrode is located based on the identified positions of both edges, and a virtual reference line BL is formed.

[0054] The edges at both ends of the receiving portion Pr can be identified by a visual sensor S as shown in FIGS.

[0055] The visual sensors S are positioned on both sides of the upper portion of the cell C to identify the end positions of the target cell C, and based on the identified end positions, set a virtual reference line BL passing through the center of the cell C. In this case, the center of the cell C corresponds to a position that is halfway based on the edge positions of both ends of the receiving portion Pr.

[0056] In this manner, each cell C has its own reference line BL.

[0057] Cell C stacking step (S2)

[0058] This is a step of stacking a plurality of cells C with the reference lines BL set thereon.

[0059] FIG. 7 shows the process of stacking a plurality of cells C.

[0060] The cells C stacked as described above are characterized in that they are stacked in a state where they are aligned so that the reference lines BL coincide with each other.

[0061] Before stacking the cells C, the positions of the cells C may differ greatly as shown in Fig. 7. The positions of the cells C are corrected so that the reference lines BL set for each of the cells C coincide with each other. At this time, the positions of the cells C are adjusted by moving them in the longitudinal direction of the cells C so that the reference lines BL coincide with each other.

[0062] When the positions of the cells C are corrected as described above and the reference lines BL set for the cells C all coincide with each other, the cells C are stacked to form one cell stack Cs.

[0063] (Second embodiment) The cell C stacking method of the present invention can be applied not only to cells C having electrode leads Le led out from both ends, but also to cells C having a pair of electrode leads Le led out from one side.

[0064] FIG. 8 shows a cell C used in the cell C stacking method according to the second embodiment of the present invention and a visual sensor S used to locate the center of the cell C, and FIG. 9 shows the cell C and visual sensor S of FIG. 8 from the side.

[0065] The cell C accommodates an electrode assembly (not shown) in which a plurality of electrodes are stacked, and as shown in Figures 8 and 9, electrode leads Le are led out from one side of the cell C, each of which is electrically connected to the electrode assembly.

[0066] The cell C stacking method of the second embodiment is also characterized in that, like the cell C stacking method of the first embodiment, a virtual reference line BL is set for each cell C to be stacked, and when stacking each cell C, the reference lines BL are aligned so that they coincide with each other.

[0067] The reference line BL corresponds to the center of the cell C, and the center of each cell C is found using the positions of both ends of the receiving portion Pr of the cell C as references.

[0068] That is, the center is the position that is halfway between the positions of both ends of the housing portion Pr.

[0069] The center of the cell C corresponds to the center of the electrode assembly, and the reference line BL is formed to pass through the center of the cell C. More specifically, the reference line BL is formed to cross the center of the cell C so that the electrode lead Le of the cell C is located on one side.

[0070] The reference line BL is set at a position corresponding to the center of the uppermost electrode of the electrode assembly contained in the housing portion Pr, i.e., the reference line BL is formed at a center position with both ends of the uppermost electrode of the electrode assembly as origins.

[0071] Both ends of the electrode included in the uppermost part of the electrode assembly correspond to positions where steps start on both sides of the receiving portion Pr.

[0072] The positions of the edges of the stacked electrodes may vary slightly. In the present invention, in order to quickly locate the center of the cell C and set the reference line BL, both edges of the electrode located at the top of the electrode assembly are identified, and the center of the electrode is located based on the identified positions of both edges, and a virtual reference line BL is formed.

[0073] The edges at both ends of the receiving portion Pr can be identified by a visual sensor S as shown in FIGS.

[0074] The visual sensors S are positioned on both sides of the upper portion of the cell C to identify the end positions of the target cell C, and based on the identified end positions, set a virtual reference line BL passing through the center of the cell C. In this case, the center of the cell C corresponds to a position that is halfway based on the edge positions of both ends of the receiving portion Pr.

[0075] In this manner, each cell C has its own reference line BL.

[0076] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0077] Cs: Cell stack C: (battery) cell Co:Edge Le: electrode lead L1: Positive lead L2: Negative lead B: Busbar S: Visual sensor BL: Reference line Pr: Storage section Pe: Derivation part

Claims

1. Setting a virtual reference line at the center of the cell; and stacking the plurality of cells having the reference lines set thereon, The cells to be stacked are stacked in a state where they are aligned so that the reference lines coincide with each other.

2. 2. The cell stacking method according to claim 1, wherein the cell contains an electrode assembly in which a plurality of electrodes are stacked, and electrode leads electrically connected to the electrode assembly are led out from both sides of the cell.

3. The cell stacking method according to claim 2 , wherein the reference line is set at a position corresponding to a center of an uppermost electrode of the electrode assembly.

4. The cell stacking method according to claim 2 , wherein the cell comprises a housing portion in which the electrode assembly is located and a lead-out portion in which an electrode lead is located.

5. A step is formed between the storage section and the outlet section, The cell stacking method according to claim 4 , wherein the central portion corresponds to a center position with respect to positions where the steps start on both sides of the accommodation portion as starting points.

6. The cell stacking method according to claim 4 , wherein the central portion of the cell corresponds to a center position with respect to edges of both end portions of the storage portion as starting points.

7. The cell stacking method according to claim 4 , wherein the center of the cell corresponds to a position that is halfway between the edge positions of both ends of the storage section.

8. The cell stacking method according to claim 2 , wherein the reference line is formed across the center of the cell so that electrode leads are located on both sides of the reference line.

9. The cell stacking method according to claim 2 , wherein the reference lines are formed at positions that are centered on both ends of the uppermost electrode of the electrode assembly.

10. the electrode assembly includes a positive electrode, a separator, and a negative electrode; the electrode leads include a positive electrode lead electrically connected to a positive electrode of the electrode assembly and a negative electrode lead electrically connected to a negative electrode of the electrode assembly; The cell stacking method according to claim 2 , wherein adjacent pairs of the cells are stacked alternately so that the positions of the positive electrode lead and the negative electrode lead are reversed.

11. The cell stacking method according to any one of claims 1 to 10, wherein the positions of the cells are adjusted by moving them in the longitudinal direction of the cells so that the reference lines are aligned.

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